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1. Field of the Invention
The invention relates to broadband systems, and in particular, to broadband systems that utilize narrowband circuit switches for various call capabilities.
2. Background of the Prior Art
Conventional circuit switches provide the backbone for many current telecommunications networks. These switches process call signaling and extend the call connection towards the destination. They have also been developed to include sophisticated capabilities. Examples include caller validation, number screening, routing, connection control, and billing. These switches are also used to deploy various services. Examples include calling cards, xe2x80x9c800xe2x80x9d calling, voice messaging, and class services.
At present, Asynchronous Transfer Mode (ATM) technology is being developed to provide broadband switching capability for telecommunications calls, which are requests for telecommunications services. Some ATM systems have used ATM cross-connects to provide virtual connections, but cross-connect devices do not have the capacity to process signaling used by telecommunications networks to set-up and tear down calls. Thus, ATM cross-connects cannot make connections on a call-by-call basis. As a result, connections through cross-connect systems must be pre-provisioned which creates a relatively rigid switching fabric. Due to this limitation, ATM cross-connect systems have been used primarily to provide dedicated connections, such as permanent virtual circuits (PVCs) and permanent virtual paths (PVPs). But, they do not provide ATM switching on a call by call basis as required to provide switched virtual circuits (SVCs) or switched virtual paths (SVPs). Those skilled in the art are well aware of the efficiencies created by using SVPs and SVCs as opposed to PVCs and PVPs because SVCs and SVPs utilize bandwidth more efficiently.
ATM switches have also been used to provide PVCs and PVPs. Because PVCs and PVPs are not established on a call-by-call basis, the ATM switch does not need to use its call processing or signaling capacity. ATM switches require both signaling capability and call processing capability to provide SVCs and SVPs. In order to achieve virtual connection switching on a call by call basis, ATM switches are being developed that can process calls in response to signaling to provide virtual connections for each call. These systems cause problems, however, because they must be very sophisticated to support current networks. These ATM switches must process high volumes of calls and transition legacy services from existing networks. An example would be an ATM switch that can handle large numbers of POTS, 800, and VPN calls.
Currently, ATM multiplexers are capable of interworking traffic of other formats into the ATM format. These are known as ATM interworking multiplexers (muxes). ATM multiplexers are being developed that can interwork traffic into ATM cells and multiplex the cells for transport over an ATM network. These ATM mux are not used to implement virtual connections selected on a call-by-call basis.
Unfortunately, there is a need for efficient systems that can integrate the capabilities of broadband components with the capabilities of conventional circuit switches. Such a system would provide ATM virtual connections on a call-by-call basis, but support the numerous services currently provided by circuit switches.
The present invention includes a telecommunications system and method for providing a service for a call. The invention operates as follows. A signaling processor receives and processes a first telecommunications signaling message for the call to provide a first control message, a second control message, and a second telecommunications signaling message. A first ATM interworking multiplexer receives narrowband traffic for the call over a first narrowband connection. It converts the narrowband traffic from the first narrowband connection into ATM cells that identify a first virtual connection based on the first control message and transmits the ATM cells over the first virtual connection. An ATM cross-connect system receives the ATM cells from the first ATM interworking multiplexer over the first virtual connection and routes the ATM cells from the first virtual connection based on the first virtual connection identified in the ATM cells. A second ATM interworking multiplexer receives the ATM cells from the ATM cross-connect system over the first virtual connection. It converts the ATM cells from the first virtual connection into the narrowband traffic and transmits the narrowband traffic over a second narrowband connection based on the second control message. A narrowband switch receives the narrowband traffic from the second ATM multiplexer over the second narrowband connection and provides a service to the call based on the second telecommunications signaling message. In various embodiments, the service provided by the narrowband switch is: routing the call, billing the call, validating the call, a calling card service, or a voice messaging service.
In various embodiments, the signaling processor selects the narrowband switch. The selection can be based on: available access to the narrowband switch, loading on the narrowband switch, an area served by the narrowband switch, network maintenance conditions, or the first telecommunications signaling message (including a destination point code, an origination point code, an NPA, an NPA-NXX, a caller""s number, an xe2x80x9c800xe2x80x9d,xe2x80x9c888xe2x80x9d, or xe2x80x9c900xe2x80x9d number, or a network identifier in the message).
In various embodiments, the signaling processor selects the first virtual connection based on: the selected narrowband switch, available access to the narrowband switch, loading on the narrowband switch, an area served by the narrowband switch, network maintenance conditions, or the first telecommunications signaling message (including a destination point code, an origination point code, an NPA, an NPA-NXX, a caller""s number, an xe2x80x9c800xe2x80x9d, xe2x80x9c888xe2x80x9d, or xe2x80x9c900xe2x80x9d number, or a network identifier in the message).
In various embodiments, the narrowband switch processes the call based on the second telecommunications signaling message. It provide a third telecommunications signaling message based on the call processing and routes the narrowband traffic for the call to the second ATM multiplexer over a third narrowband connection. The signaling processor receives and processes the third telecommunications signaling message to provide a third control message to the second ATM multiplexer, and to provide a fourth control message. The second ATM interworking multiplexer receives the narrowband traffic for the call from the narrowband switch over the third narrowband connection. It converts the narrowband traffic from the third narrowband connection into ATM cells that identify a second virtual connection based on the third control message and transmits the ATM cells over the second narrowband connection. The ATM cross-connect system receives the ATM cells from the second ATM interworking multiplexer over the second virtual connection and routes the ATM cells from the second virtual connection based on the second virtual connection identified in the ATM cells. A third ATM interworking multiplexer receives the ATM cells from the ATM cross-connect system over the second virtual connection. It converts the ATM cells from the second virtual connection into the narrowvband traffic and transmits the narrowband traffic over a fourth narrowband connection based on the fourth control message. In various of these embodiments, the signaling processor selects the second virtual connection based on a destination point code in the third telecommunications signaling message or based on a destination network identified in the third telecommunications signaling message.